Observations that implicate the aromatic amine procainamide but not its acetylated metabolite, N-acetylprocainamide (NAPA) as a cause of systemic lupus erythematosus have been made (N.E.J.M. 1979; 301:1382-1385). We shall extend these observations by treating patients who had procainamide lupus with NAPA chronically and observe the clinical and immunologic response. We shall also develop a mouse model for procainamide lupus to see if other amine including hair dye and food dye constituents can incite the lupus. We will do a case-control epidemiologic study to assess the association of hair colorant exposure with idiopathic systemic lupus erythematosus.